From db4e408ca9dab18c6f80c9e0522b19bc80a924b9 Mon Sep 17 00:00:00 2001
From: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Date: Tue, 3 Dec 2024 14:06:17 +0100
Subject: [PATCH] QMap/QHash: mark isEmpty() / empty() as [[nodiscard]]

Cone of shame, they should've been marked as such since day 1.

Change-Id: I9aaf6567e183e4ece5443f4fbf12eb3a251501d5
Pick-to: 6.5
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit 091bb2f997c2bbe4e44d66527f13c435288e0562)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/corelib/tools/qhash.h | 5 +++++
 src/corelib/tools/qmap.h  | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/src/corelib/tools/qhash.h b/src/corelib/tools/qhash.h
index 8446e82624a..62f7e9be640 100644
--- a/src/corelib/tools/qhash.h
+++ b/src/corelib/tools/qhash.h
@@ -929,6 +929,8 @@ public:
 #endif // Q_QDOC
 
     inline qsizetype size() const noexcept { return d ? qsizetype(d->size) : 0; }
+
+    [[nodiscard]]
     inline bool isEmpty() const noexcept { return !d || d->size == 0; }
 
     inline qsizetype capacity() const noexcept { return d ? qsizetype(d->numBuckets >> 1) : 0; }
@@ -1363,6 +1365,7 @@ public:
     size_t bucket_count() const noexcept { return d ? d->numBuckets : 0; }
     static size_t max_bucket_count() noexcept { return Data::maxNumBuckets(); }
 
+    [[nodiscard]]
     inline bool empty() const noexcept { return isEmpty(); }
 
 private:
@@ -1609,6 +1612,7 @@ public:
 
     inline qsizetype size() const noexcept { return m_size; }
 
+    [[nodiscard]]
     inline bool isEmpty() const noexcept { return !m_size; }
 
     inline qsizetype capacity() const noexcept { return d ? qsizetype(d->numBuckets >> 1) : 0; }
@@ -2118,6 +2122,7 @@ public:
     size_t bucket_count() const noexcept { return d ? d->numBuckets : 0; }
     static size_t max_bucket_count() noexcept { return Data::maxNumBuckets(); }
 
+    [[nodiscard]]
     inline bool empty() const noexcept { return isEmpty(); }
 
     inline iterator replace(const Key &key, const T &value)
diff --git a/src/corelib/tools/qmap.h b/src/corelib/tools/qmap.h
index 326ae7d8a51..0fd025e2b70 100644
--- a/src/corelib/tools/qmap.h
+++ b/src/corelib/tools/qmap.h
@@ -267,6 +267,7 @@ public:
 
     size_type size() const { return d ? size_type(d->m.size()) : size_type(0); }
 
+    [[nodiscard]]
     bool isEmpty() const { return d ? d->m.empty() : true; }
 
     void detach()
@@ -759,6 +760,7 @@ public:
     }
 
     // STL compatibility
+    [[nodiscard]]
     inline bool empty() const
     {
         return isEmpty();
@@ -938,6 +940,7 @@ public:
 
     size_type size() const { return d ? size_type(d->m.size()) : size_type(0); }
 
+    [[nodiscard]]
     bool isEmpty() const { return d ? d->m.empty() : true; }
 
     void detach()
@@ -1518,6 +1521,7 @@ public:
     }
 
     // STL compatibility
+    [[nodiscard]]
     inline bool empty() const { return isEmpty(); }
 
     std::pair<iterator, iterator> equal_range(const Key &akey)